Conventionally, pumps have been used to draw up from lower levels or push up to higher levels regular liquids or liquids which include viscous substances or solid substances such as sand and pebbles. Various types of pumps have been developed in accordance with the type and nature of the objects to be transferred; however, there have been a number of problems. Namely, they are not applicable for all purposes; rather their applicability is limited to each specific purpose; they are expensive; the transferable distance is short; the transferable quantity of liquid is small; and they consume much energy.
Therefore, it is necessary to connect many pumps, like relay stations, in order to draw up liquid from more than several hundred meters below ground level, or to push it up several hundred meters above the ground level. In addition to the height and the depth, the extent of the area to which the liquid is supplied affects the number of the pumps. Many pumps are inevitably required in order to supply liquids to many points extending over a wide area. To construct special kinds of pumps, or to increase the number of pumps, invites an additional investment compared with the use of only one motor, as well as increased equipment costs. Particularly in the case of liquid which contains sludge or solid substances, mechanical durability is decreased because the structure of the pump allows viscous or solid substances to enter its mechanism, which leads to frequent repairs and replacement of components caused by breakdown and wear. Besides, pumps are helpless against freezing of the liquid contained in the pumps themselves.
Pumps have played a great role in displacing various liquids, thereby providing them with potential energy. It is not too much to say that man has been completely dependent on pumps. Pumps, however, have the problems as stated above. Stated in relation to this invention, these problems are as follows.
(1) Pumps which draw up or push up liquids which contain viscous or solid substances are, in general, expensive and have high operating costs, and their transferable distance is short. For this reason, when spreading a large quantity of liquid over a wide area along the slopes of mountains higher than several hundred meters, or when flowing back a large quantity of water to an upper reservoir utilizing excess electricity during the night at hydroelectric power plants, or when removing or gathering sand and pebbles or other deposits on water bottoms, it becomes necessary to operate a large pump, or many pumps, like relay stations, and since breakdown of one unit damages the operation of the whole system, sophisticated instrumentation is required, including measures against breakdown, which necessitates large expenditures on the equipment. Whenever pumps are used, these are unavoidable problems.
(2) Particularly when drawing up or pushing up liquids containing viscous or solid substances, repairs and replacement of components are necessary due to breakdown or wear in the mechanism, and the mechanical durability is decreased because the mechanical structure of pumps allows the substances to run against the pump mechanism through which the liquids flow.
(3) In the winter season, lagging and heating are required for pumps and connected pipes in order to prevent freezing. At present, there have been provided no effective freeze-prevention measures for pumps and pipes to be installed over a wide area, so that pumps and connected pipes often burst or get damaged by a cold wave, thereby causing the operation to halt. Complete freeze-prevention is not currently realistic because of the excessive costs involved. In order to resolve these problems, it is necessary to move away from pumps that include a mechanical structure which acts on the liquids directly to draw up or push up the liquids, and to establish novel transfer methods and equipment based upon a new concept.